An organic light-emitting display utilizes the self-illuminating feature of organic semiconductor materials for display, and has advantages such as high contrast, low power consumption, etc. Often, a pixel array comprising a plurality of sub-pixels is disposed in the display region of the organic light-emitting display. Each sub-pixel includes an organic light-emitting diode and a driving transistor that drives the organic light-emitting diode to emit light.
The light-emitting current of the organic light-emitting diode is related to the voltage difference Legs between the gate electrode and the source electrode of the driving transistor, and is related to the threshold voltage Vth of the driving transistor. However, the threshold voltage Vth of the driving transistor may drift (i.e., “threshold drift”) due to reasons regarding the fabrication process, and aging after long-time use, etc. Accordingly, the light-emitting brightness of the organic light-emitting device may be unstable.
To compensate the threshold voltage of the driving transistor, one existing type of organic light-emitting display panels may write an initialization signal into the gate electrode and the source electrode of the driving transistor via the reference voltage signal line and the date line. Further, the reference voltage signal line is utilized to collect the threshold voltage of the driving transistor. After an external compensating circuit is applied to compensate the threshold voltage of the driving transistor, a driving signal configured to control the light-emitting brightness of the organic light-emitting diode is written into the driving transistor again via the reference voltage signal line and data line.
According to the present disclosure, in such organic light-emitting display panel, the reference voltage signal line is not only configured to provide the initialization signal and the driving signal, but also configured to collect the threshold voltage. Thus, the working status of the reference voltage signal line may be unstable. Further, to save the wiring number and space, a plurality of sub-pixels may utilize the same reference voltage signal line for signal write-in and threshold voltage collection. Accordingly, the working status of each reference voltage signal line in a period of displaying one frame image may need to be switched a couple of times, which increases the load of the driving chip configured to control the reference voltage signal line.
In addition, a plurality of sub-pixels connected to the same reference voltage signal line are located at different positions, and the threshold voltages of the driving transistors at different locations fed back to the driving chip by the reference voltage signal line may have a certain voltage drop. During compensation, the compensated data signal is inputted via the data line. For the same sub-pixel, the variance in the voltage of the data signal transmitted by the data line, is different from the variance in the threshold voltage collected and transmitted to the driving chip by the reference voltage signal line, such that accuracy and balance of the display brightness of each sub-pixel can hardly be ensured.
The disclosed organic light-emitting display panel and driving method thereof. and organic light-emitting display device are directed to solving at least partial problems set forth above and other problems.